mirror of https://github.com/Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
108 lines
3.1 KiB
108 lines
3.1 KiB
/* SPDX-License-Identifier: GPL-2.0 */ |
|
#ifndef _ASM_S390_ALTERNATIVE_ASM_H |
|
#define _ASM_S390_ALTERNATIVE_ASM_H |
|
|
|
#ifdef __ASSEMBLY__ |
|
|
|
/* |
|
* Check the length of an instruction sequence. The length may not be larger |
|
* than 254 bytes and it has to be divisible by 2. |
|
*/ |
|
.macro alt_len_check start,end |
|
.if ( \end - \start ) > 254 |
|
.error "cpu alternatives does not support instructions blocks > 254 bytes\n" |
|
.endif |
|
.if ( \end - \start ) % 2 |
|
.error "cpu alternatives instructions length is odd\n" |
|
.endif |
|
.endm |
|
|
|
/* |
|
* Issue one struct alt_instr descriptor entry (need to put it into |
|
* the section .altinstructions, see below). This entry contains |
|
* enough information for the alternatives patching code to patch an |
|
* instruction. See apply_alternatives(). |
|
*/ |
|
.macro alt_entry orig_start, orig_end, alt_start, alt_end, feature |
|
.long \orig_start - . |
|
.long \alt_start - . |
|
.word \feature |
|
.byte \orig_end - \orig_start |
|
.byte \alt_end - \alt_start |
|
.endm |
|
|
|
/* |
|
* Fill up @bytes with nops. The macro emits 6-byte nop instructions |
|
* for the bulk of the area, possibly followed by a 4-byte and/or |
|
* a 2-byte nop if the size of the area is not divisible by 6. |
|
*/ |
|
.macro alt_pad_fill bytes |
|
.fill ( \bytes ) / 6, 6, 0xc0040000 |
|
.fill ( \bytes ) % 6 / 4, 4, 0x47000000 |
|
.fill ( \bytes ) % 6 % 4 / 2, 2, 0x0700 |
|
.endm |
|
|
|
/* |
|
* Fill up @bytes with nops. If the number of bytes is larger |
|
* than 6, emit a jg instruction to branch over all nops, then |
|
* fill an area of size (@bytes - 6) with nop instructions. |
|
*/ |
|
.macro alt_pad bytes |
|
.if ( \bytes > 0 ) |
|
.if ( \bytes > 6 ) |
|
jg . + \bytes |
|
alt_pad_fill \bytes - 6 |
|
.else |
|
alt_pad_fill \bytes |
|
.endif |
|
.endif |
|
.endm |
|
|
|
/* |
|
* Define an alternative between two instructions. If @feature is |
|
* present, early code in apply_alternatives() replaces @oldinstr with |
|
* @newinstr. ".skip" directive takes care of proper instruction padding |
|
* in case @newinstr is longer than @oldinstr. |
|
*/ |
|
.macro ALTERNATIVE oldinstr, newinstr, feature |
|
.pushsection .altinstr_replacement,"ax" |
|
770: \newinstr |
|
771: .popsection |
|
772: \oldinstr |
|
773: alt_len_check 770b, 771b |
|
alt_len_check 772b, 773b |
|
alt_pad ( ( 771b - 770b ) - ( 773b - 772b ) ) |
|
774: .pushsection .altinstructions,"a" |
|
alt_entry 772b, 774b, 770b, 771b, \feature |
|
.popsection |
|
.endm |
|
|
|
/* |
|
* Define an alternative between two instructions. If @feature is |
|
* present, early code in apply_alternatives() replaces @oldinstr with |
|
* @newinstr. ".skip" directive takes care of proper instruction padding |
|
* in case @newinstr is longer than @oldinstr. |
|
*/ |
|
.macro ALTERNATIVE_2 oldinstr, newinstr1, feature1, newinstr2, feature2 |
|
.pushsection .altinstr_replacement,"ax" |
|
770: \newinstr1 |
|
771: \newinstr2 |
|
772: .popsection |
|
773: \oldinstr |
|
774: alt_len_check 770b, 771b |
|
alt_len_check 771b, 772b |
|
alt_len_check 773b, 774b |
|
.if ( 771b - 770b > 772b - 771b ) |
|
alt_pad ( ( 771b - 770b ) - ( 774b - 773b ) ) |
|
.else |
|
alt_pad ( ( 772b - 771b ) - ( 774b - 773b ) ) |
|
.endif |
|
775: .pushsection .altinstructions,"a" |
|
alt_entry 773b, 775b, 770b, 771b,\feature1 |
|
alt_entry 773b, 775b, 771b, 772b,\feature2 |
|
.popsection |
|
.endm |
|
|
|
#endif /* __ASSEMBLY__ */ |
|
|
|
#endif /* _ASM_S390_ALTERNATIVE_ASM_H */
|
|
|